The invention relates to a sound-wave-coupling rotational flow-rotation eliminating efficient dust removing and defogging device. The sound-wave-coupling rotational flow-rotation eliminating efficient dust removing and defogging device is arranged above a spraying layer in a desulfurization absorption tower and comprises a plurality of dust removing and defogging units which are parallelly mounted. Each dust removing and defogging unit comprises an outer cylinder, a primary centrifugal rotational-flow plate, a secondary centrifugal rotational-flow plate and a rotation-eliminating hydrophobic plate, wherein the primary centrifugal rotational-flow plate and the secondary centrifugal rotational-flow plate are sequentially parallelly arranged in the outer cylinder from bottom to top, the rotation-eliminating hydrophobic plate is obliquely arranged at the top of the outer cylinder, a sound wave generator is arranged at the center of the primary centrifugal rotation-flow plate, and a washing water sprayer is arranged between the sound wave generator and the secondary centrifugal rotation-flow plate. Compared with the prior art, the sound-wave-coupling rotational flow-rotation eliminating efficient dust removing and defogging device has the advantages that the device integrates the features of sound wave and rotational-flow centrifugal dust removing and defogging, and the device is simple and compact in overall structure, low in investment cost, good in operation stability, free of scaling and blocking risks, capable of achieving deep dust removing and defogging of saturated wet flue gas after desulfurization under low investment cost and operation cost, low in resistance loss and promising in application prospect.